which fuel has more potential?

[stang99x]

I thought about this the other day at a station that has 87, 89, 93, 104E85, and 87 Ethanol free. My question is, which has more potential, the 87 with no ethanol or the 93 with a questionable amount of ethanol in it. I only as seeing as the nonethanol isn't watered down like the rest of the gas we get. Curious to hear some of the gas/oil guru's asnwer this one

 

[hand-filer]

A no brainer really. Higher octane = more power potential.

 

[stang99x]

A no brainer really. Higher octane = more power potential.

I think we all know that, but I'm talking chemical composition of pure gasoline slightly less refined than a more refined gas that has been watered down with ethanol.

 

[4VFTW]

you answered your own question with the 1st part of the sentence.


/end thread

 

[zinc03svt]

93 clear ethanol free as a standalone. Tune for the same stoich for best results.

 

[stang99x]

93 clear ethanol free as a standalone. Tune for the same stoich for best results.

I've not seen 93 ethanol free at any stations around here. I've only seen 87. It seems that some want to answer with stupidity instead of seriousness, even the most basic retard knows the octane basis. I was curious more for someone who has in depth knowledge of chemical compositions and the potential energy of fuels that aren't watered down. Many newer vehicles even say not to use gas with any ethanol content. So my curiousity stemmed more from potential theoretical energy than simple octane rating

 

[97tc]

Gasoline has more heat energy,(btu's), than ethanol. Ethanol has about 60% of the energy as pure gasoline. Nitro methane has about 1/3 but since its self oxygenated you can run it just at the edge of hydrostatic lock.

 

[Jumpmaster2015]

The octane rating does not measure potential, but rather how resistant to knock that particular fuel is. If you want "potential" switch to E85. You can run a ton of extra timing with that fuel.

 

[4VFTW]

The octane rating does not measure potential.

please elaborate

 

[debit_free_2010]

The octane rating does not measure potential, but rather how resistant to knock that particular fuel is. If you want "potential" switch to E85. You can run a ton of extra timing with that fuel.

I'm with 4VFTW on that one, Octane rating most certainly does indicate a fuels potential to make more power, I'll agree, octane doesn't make any power by itself but it does allow you to run more timing/compression/boost which will result in a power increase.

As for the OP's question, regardless of the octane rating, 1 gallon of pure gasoline has 114000 BTU's.

E10 OToH has 112,000 BTU so it will make less power but it's not enough to go out of one's way to chose one over the other.

My old blown 3v made 600+ rwhp all day long on BP-93 which from some analysis had upwards of 15% ethanol in it.

 

[AKDMB]

e85 has way more potential than 93, especially in boosted applications, it's nice with NA applications too, just for the extra knock protection. In boosted applications you could pick up 50+rwhp with e85 easy over 93.

Here's a thread, +60rwhp/+34ft-lb's, boosted of course:

http://www.svtperformance.com/forums/showthread.php?949715-Joined-the-Paxton-Club-93-vs-E85-dyno-sheet

 

[Jumpmaster2015]

please elaborate

I have always been told that by definition the octane level measures the ability for the fuel to resist detonation. I wasn't trying to cause a debate, I was just three sheets to the wind last night lol.

 

[mattaglover]

I have always been told that by definition the octane level measures the ability for the fuel to resist detonation. I wasn't trying to cause a debate, I was just three sheets to the wind last night lol.

I believe you are basically saying the same thing they are. The higher the octane the more resistant to knock therefore more power. You are not wrong by any means. The answer to the thread though is like said above. Higher octane so e85 more timing more power.

 

[Roushcornfed]

Do not run 93, 91,87 ethanol free gas unless you want less knock protection period. We have seen endless cars come in on the dyno and knock with tunes because they think ethanol free is best. Empty 93 with no ethanol and Switch gas to 93 ethanol no more knock. Very very common i witnessed it even with my own a few years ago. If you have a power adder e85 is a no brainer.